Occurrences of heavy metal in breast milk in China: Results of the third National Breast Milk Survey

To investigate the exposure of infants to heavy metal during lactation, breast milk from 24 provinces in China were detected. Among As, Cd, Cr, Hg, and Pb, the detection frequencies of As (85%, 0.50 μg/L) and Cd (91%, 0.15 μg/L) in breast milk were notably high. The concentrations of As in breast milk from coastal provinces were significantly higher than those in inland provinces, the discrepancy that was strongly associated with the intake of seafood. The levels of Cd in breast milk were markedly higher in southern provinces than those in northern provinces, the distinction that was significantly linked to the dietary consumption of Cd. Contrasting with the findings of the second national breast milk survey in China, the levels of As, Cd and Pb in the third one decreased evidently. Moreover, comparing to the global levels of heavy metals in breast milk, their levels in Chinese breast milk were comparatively low. Risk assessment for infants showed that heavy metals in breast milk from most regions of China did pose no health hazard. Continuous monitoring of heavy metal levels in breast milk is crucial for the health of breastfed infant.